I understand that Access stores information as members not as related records...that being said.

I have a large set of data with a userid field, receipt check time and date. Each userid has approx. 150 receipt check times in a day. I need to calculate the individual duration time of each receipt check. In excel, I sorted the time by date, userid name, and receipt check time ascending. If the userid in row b was equal to userid in row a, I would subtract row a receipt check time from row b receipt check time to give a duration time.

If I understand correctly, if receipt check 1 happens at 10:00 and receipt check 2 at 10:15, you need receipt check 1 to reflect a 15 min duration, right?

Someone else might have a simpler method, but you could always do it in VBA by creating a recordset (filtered by date and userid) then move through the records from last to first (Do until BOF, Previous, Loop), capturing the last time then subtracting the time from the one previous to get the elapsed time. Store that time in the current record, then move to the previous and so on until you are through all the records.

I haven't tested this, so anyone who knows, please shout out if there is a better way.

I'm lost on the language for storing a field value moving to the previous one and subtracting that stored value into an output for a new field on that record. These timestamps are in a field called timeaccurate.